Pump



May 29, 1945. c. c. s. LE CLAIR 2,377,251

PUMP

Filed May 22, 1944 2 Sheets-Sheet 1 mula ln o, "am

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My 29, 1945. c. c. s. LE CLAIR 2,377,251

i I PUMP a I .Filed May 22, 1944 2 sheets-sheet 2 Patented May 29, 1945UNITED STATES PATENT OFFICE PUMP @'ainille' Glare' Slfnklig: Le Clair,Acton',y London,A England Application Mayzz, 1944;,,SerialA ne. sae-,69anl Greavrliain May 26; 19113V e claims. rel. ree-e411) the leakage ofthe liquid and, obviously; the

fewer leakage paths there are the better". One of the main leakage pathsin a plunger type of pumpris lol'etiveer'lv the plunger and its cylinderor" past its stuflingv box if sileli is tted.

According. to the'pes'ent inventio,. a pump is characterized by thefeature that the pumping operations are carried out by at leastonehollow collapsible and expansible pumlg'lrgv member arranged withinal container for fluids,i meansi for causing the pressure of the fluidwithin` the container to fluctuate so to cause the collapsing and (or)expanding off the member' in order to change the container volumemof thememben an inlet Val-vey for permitting fluid from a supplyr source toenter the member when the latter is expanded,4

and an outlet valve for permitting fluid, drawn into-the member when themember is expanded, to be dischargedA from the member tor. the` place ofuse of the fluid when the member is collapsed.

lThe said collapsible and eiiparisible hollow member may take variousforms. For example,` tmay consist of a bellows-like device, a-tube ofelliptical section, which may either be straight or curved, in themanner of= aBourdolr tube.

By theuse of such a pumpingvmemberinot only i is the principal leakagepath eliminated, but stop means may be provided for limiting` its travelor pulsationso that its discharge per` pulsation may be reducedto somepredetermined and exceedingly small quantity. In this way, a pump havingan extremely small deliveryl can be constructed without resort to partstoo Smalll for satisfactory manufacture.

As mentioned above, according to the present invention, the saidhollowpumping member is expanded and oollapsedvby uctuating fluidpressure, such as*l hydraulic, actingupon the member, and in order toaccomplish this, the meln ber is arranged within a pressure tightcontainer wherein the pressure may be 'i'lctuated through apredetermined range.

Such an arrangement has several advantages. For example, tpermit'sv amultiplicity of collapsible and expansible pumping elements, eachcapaille of' extremely small discharge; i0- iiehoused within onecontainer, the pressure 'withir'iA which te fleiuaijed by" a'siiiglepump of malicia@7 4israeley Furnier, byl limiting the rangecf againstwhich eaclijindlvidual pumping' element will deliver; maybe-limited tesuinesil-fefiguresow that, sliciilil' a delivery pipejlieecnieClegg-"eliv up;

, for example; hiep-fessure will fiot'loilil'cl` up u'iiiiil'riaeuieialfesplace. A p

iiiadiiliigm' iothesiijmesnsrefeired-i above,

.trisL discharge eerriiulsiieri may be een:

vieil-eil1 by verving' v1li@ design df trie" pumping meneer; Thil-s, ifitrie of a time fleliiisticai Fig.- 2` is' a sectionall View of amodification iii llich the pumping members consist of cu'vd" ellipticaltubes.

A number Of hollow, metallic collapsible fnen'lbers I are mountedin'side apressure-tigl'lt c'orltainer 2. 'l'hese collapsible members arein the form of bellows; as .previously mentioned.

f be` adjusted axially' and fixed iii its adl'usiii position livA alockiiuts: The 'plunge-'ris fclir'iled through which a fresh charge ofoil is admitted when the bellows expands, the oil being taken through a.pipe I6 from an oil supply source I1 external to the pressure tightcontainer 2 but adjacent thereto and integral therewith.

The fluctuating pressure is provided by a single pump, hereinaftercalled the main pump, comprising a plunger I8 operatingpin a cylinder I9integral with the container 2 and oil supply source I1.

This pump cylinder I9 is provided with an inlet port 20 adapted to beuncovered by the plunger I8 at the end of its outward or suction stroke.There is no discharge Valve in the ordinary sense of the term, but arelief valve 2| is fitted between the pressure-tight container and theoil supply source I'I such that should the pressure in the former risebeyond a predetermined figure, the valve allows any excess oil to returnto the supply source. The pump plunger is pressed outwards by a spring22 and operated by a rotating shaft 23 and eccentric or cam 24.

At the outward end of the inlet stroke of the plunger I8, the inlet port2U is uncovered and oil from the supply source flows into and chargesthe cylinder I9. On its inward or discharge stroke the plunger rstcloses the inlet port 20 and then forces the entrapped oil forwardthrough a port 25 into the pressure-tight container 2, raising thepressure in the container andat the same time collapsing all thecollapsible bellows I and discharging a predetermined quantity of oilfrom each. If, as will generally occur, this takes place before the mainpump has finished its stroke, any excess oil'delvered by the latter willpass through the said relief valve 2| back to the supply source I'I. Onthe next suction stroke of the main pump this amount plus the amountdischarged by the bellows will pass once again through the inlet passage2U into the pump cylinder and the cycle will be repeated.

The construction shown in Fig. 2 is similarto that shown in Fig. 1 inthat it comprises a pressure-tightcontainer 2A which is closed by acover 1A and is integral with an oil supply source IIA. A hollow housing6A is attached to the cover 1A and spring-urged inlet and outlet valvesIA and |3A are also fitted. The outlet valves provide communication withoutlet pipes I4A leading to the place of use of the oil and the inletvalves connect with the inlet pipes IBA leading from the supply sourceI1A. A relief valve 2IA is also fitted. Instead of bellows devices,`however, use is made of curved metal tubes 26 of elliptical sectionVresembling Bourdon tubes. The upper end of each tube communicates withthe passage IIA in the housing BA while its lower end is closed by a cap21. As in the preceding construction, the apparatus is provided with amain pump comprising a plunger IBA slidable in a cylinder ISA, an inletport A providing communication between the interior of the cylinder andthe oil supply source I'IA when the plunger is at the end of its suctionstroke, and an outlet port A providing yconstant communication betweenthe cylinder and the pressure-tight container 2A. The plunger isoperated by a cam or eccentric 24A mounted on arctating shaft 23A. Onthe discharge stroke of the plunger IBA, oil under pressure is forcedfrom the cylinder ISA through the port 25A into the container 2A. Thepressure of the oil in the container alters the section and shape of,and collapses, the tubes 26 thereby forcing oil from the tubes into thehollow interior of the housing 6A, andA thence past the outlet valvesI3A through the discharge pipes I4A to the place of use. Towards the endof the discharge stroke of the plunger IBA after the tubes 26 havecollapsed any excess oil delivered is discharged back to source via therelief valve ZIA. When the plunger I8A is moved in the oppositedirection, however, the pressure immediately drops, the tubes 26 againexpand and oil is drawn from the oil supply source ITA through the pipesISA and past the inlet valves I5A into the interior of the housing 6Aand into the tubes 26 to replace that previously expelled from thelatter. At the end of the suction stroke, the inlet port 20A is oncemore uncovered and the pump chamber is replenished as previouslyexplained.

The tubes 26 could be straight instead of being curved. Whatever form ofpumping member is used, however, it is desirable that the whole of theinternal container volume of the member with its associated passagesfrom the inlet valve to the discharge valve should have an upward trendtowards the latter so that any air which may gain admission can find itsway past the discharge valve by levitation.

Stop means (not shown) may be provided for limiting the collapsing ofthe elliptical tube and such means may be adjustable.

In the construction shown in Fig. 1, the stop means 4 may be external tothe collapsible members, limiting their free shape, instead of limitingtheir collapsed shape internally as shown.

The main pump may draw fluid from, and discharge fluid past the reliefvalve 2I or 2IA back to, a supply source separate from that from whichthe collapsible members draw their supply, and the main pump may itselfbe separate from either the supply source or the pressure container andconnected thereto by pipe connections.

It will be understood that the pump may be constructed in the form of amultiple pump unit as described above, which comprises two or morecollapsible and expansible or flexible pumping members, or it maycomprise a single pumping member. A multiple pump unit may comprise oneor more main pumps and the pumping members may be arranged in the sameor in indi- Vidual pressure-tight containers.

I claim:

1. A pump comprising a pressure type container for fluids, at least onehollow collapsible and expansible pumping member within said container,a source of fluid to be pumped, at least one main pump which receivesfluid from said supply source and forces it into said container so as tocause the pressure of the fluid in said container to fluctuate therebycausing said member to collapse and expand to change its containervolume, at least one hollow housing associated with said containerhaving an inlet port and an outlet port, check valves controlling the owof iiuid through said ports, said member being mounted to communicatewith the interior of said housing, and means connecting the inlet portwith said fluid source.

2. The combination set forth in claim 1 wherein said hollow collapsibleand expansible pumping member consists of a bellows device.

3. The combination set forth in claim l wherein said hollow collapsibleand expansible pumping member consists of a, tube of elliptical section.

4. The combination set forth in claim l including stop means positionedto limit the extent of movement of said pumping member, so that itsdischarge per pulsation may be reduced to some predetermined and smallquantity.

5. The combination set forth in claim 1 wherein said hollow collapsibleand expansible pumping member consists of a bellows device, andincluding stop means to limit the extent of movement of said bellowsdevice.

6. The combination set forth in claim 1 wherein said hollow collapsibleand expansible pumping member consists of a bellows device, andincluding adjustable stop means to limit the extent of movement of saidbellows device to any desired and predetermined amount.

7. The combination set forth in claim 1 wherein said source of uid is incommunication with the main pump cylinder through an inlet portcontrolled by the pump plunger, and wherein the main pump cylinder 1s inconstant communication with said container through an outlet port.

8. The combination set forth in claim l wherein said source of fluid isin communication with the main pump cylinder through an inlet portcontrolled by the pump plunger, and wherein the main pump cylinder is inconstant communication with said container through an outlet port, andincluding pressure-relief means in said container to allow any excessfluid to be returned to said source whenever the pressure in saidcontainer rises above a predetermined value.

CAMILLE CLARE SPRANKLING LE CLAIR.

